The Federal Aviation Administration said on Sunday that a new telecommunications issue at the facility that guides aircraft at Newark Liberty International Airport forced the agency to briefly slowed aircraft in and out of the airport.

Caught in the middle of the issues at Newark is United Airlines, which is the most active airline at the New Jersey airport. While the problems lie with the FAA system, the airline is where people often aim their frustrations over cancellations and delays.

Similar to last summer, there is currently a nationwide shortage of air traffic controllers, which will “take time” to replenish, according to Transportation Secretary Sean Duffy.

United Airlines Holdings Inc. expects flight reductions at Newark airport to linger through summer and into fall as the crucial travel hub struggles to recover from air traffic control glitches that have already disrupted hundreds of flights.

Newark Liberty International Airport is facing another FAA-imposed ground delay due to staffing shortages, after a telecommunications issue led to delays on Sunday.

Transportation Secretary Sean Duffy detailed his plan to update Newark Liberty International Airport‘s infrastructure to address recent outages, blaming the Biden administration for the current problems.